C. didactylus ranges through Venezuela (the delta and south of the Río Orinoco) and the Guianas (French Guiana, Guyana, and Suriname) south into Brazil (Maranhão state west along the Rio Amazonas/Solimões) and west into the upper Amazon Basin of Ecuador and Peru. Its southern limit in the western Amazon of Brazil is unclear. It occurs in the southern departments of Colombia, with its northern limit being the departments of Meta and Guainía. It ranges from sea level up to 2,438 m asl (Britton 1941).